with regards to the "carrying handle" in the centre of the faceplate of the Ukw.E.e, MWEC, 10 W.S.c and similar, some are hinged and some are not. The hinged detail makes sense so that they clear the cover plate.

Does the non hinged type have a deeper sheet metal casing in order to clear the handles, or have I misinterpreted how much the casing extends past the main body of the units and the height of the carrying handles?

The "non-hinged" type is prevalent on Telefunken designed equipment, while most Lorenz designed equipment has a hinged handle. The exception is perhaps the Mw.E.c which also has a hinged handle. There is more space behind the hinged versions, when folded flat, the hinged and non-hinged types protrude about as much. I think the reason behind the Mw.E.c hinged design is that the faceplate is rather "busy" with controls, so with an unhinged type you will struggle to get your fingers behind it without scraping your knuckles on a sharp ridge.

I hadn't considered the effect that the handles might have when they were flat.

May I ask for a measurement for the overhang of the sheet metal casing from the main faceplate please. I originally guesstimated it at 16-17mm, (from photos), but that makes the space for fingers under the hinged handle very small, especially for my chubby fingers!